A metal-oxide-semiconductor (MOS) transistor is one of the most important elements in modern integrated circuits. The basic structure of a MOS transistor includes a semiconductor substrate; a gate structure on the semiconductor substrate. The gate structure includes a gate dielectric layer on the surface of the semiconductor substrate and a gate electrode layer on the surface of the gate dielectric layer; and doped source and drain regions in the semiconductor substrate on both sides of the gate structure.
A conventional planar MOS transistor has weak control capability on the channel current with respect to the development of semiconductor technology, causing serious leakage current. A fin field effect transistor (Fin FET) is an emerging multi-gate device which generally includes a fin that protrudes from the surface of the semiconductor substrate; a gate structure covering a portion of the top surface and a portion of sidewall of the fin; and doped source and drain regions in the fin on both sides of the gate structure.
However, performance of the semiconductor devices of conventional MOS transistors and fin field effect transistors still needs to be improved.
The disclosed method for fabricating a semiconductor device is directed to solve one or more problems set forth above and other problems in the art.